Expose everywhere

[Ms2ger]

Ref: tc39/proposal-shadowrealm#331

[shaseley]

This would expose the interfaces on other globals (i.e. worklets), but wouldn't make them particularly useful since they're used in conjunction with self.scheduler, exposed here via a WindowOrWorkerGlobalScope mixin. If we were to change that, we'd need to also update some of the algorithms since we assume either a window or worker (e.g. step 7 here).

But I'm wondering whether or not worklet global scopes (and maybe by extension shadow realms) should expose a Scheduler. Scheduler runs tasks async and is tightly coupled with the event loop; worklets seem to have different expectations around the event loop and asnyc tasks, specifically that spec text leads me to believe they shouldn't be running async tasks (the part about not needing to run continuously). I'm not all that familiar with worklets, however.

/cc @domenic who might have some more context/thoughts.

[domenic]

Yeah. Although I applaud the general tendency toward being maximal in what we expose, I think the particular case of scheduling---both this API, and things like setTimeout/setInterval---are probably best not exposed in all realms.

In particular, worklet realms are designed to have a minimal event loop, that could be implemented as only ever running one task + associated microtasks, per instantiation of the WorkletGlobalScope. So anything that allows scheduling work in separate future tasks would break that.

[Ms2ger]

@domenic oh, looks like I missed the comments here before. I don't have strong feelings about this myself; this PR was based on my understanding that you & Dan had agreed it would be useful to expose. Unless @leobalter disagrees, I'm happy to drop this if you changed you mind, though.

[leobalter]

I'm fine with it either way.

cc @caridy